1. Field of the Invention
This invention relates to photographic camera apparatus and, more particularly, to photographic camera apparatus of the folding type including a collapsible opaque exposure chamber and a collapsible flare baffle positioned within the exposure chamber to reduce flare light.
2. Description of the Prior Art
Many photographic cameras have objective lenses which are capable of satisfactorily imaging areas of object space that are larger than the area desired to be recorded when a picture is taken. As a consequence of this, unwanted radiation having its origins outside of a camera's desired field of view may enter the interior of the camera where it can reflect from internal surfaces and eventually strike the film's photosensitive surface. When this occurs, depending on the nature of the internal reflection, either extraneous images are formed in the picture or an overall fog is created which causes a reduction in picture contrast. In either case, the quality of the final picture may be seriously degraded unless suitable means are provided for preventing the unwanted radiation or flare light from reaching the film during exposure.
Those skilled in the photographic arts have recognized this long standing problem and have provided solutions in a variety of forms. Examples of traditional solutions include the use of liner materials, such as flocking, placed on interior camera surfaces to absorb stray radiation or flat black paint to reduce reflections. Another well known solution involves the provision of baffles arranged perpendicular to the camera's optical path to intercept the unwanted radiation to prevent it from ever reaching the film. While these solutions are quite adequate, they evidently have their greatest utility in non-folding type cameras where size, cost, and manufacturing considerations are relatively unimportant.
Another well known solution which has particular application in non-folding type cameras is disclosed in U.S. Pat. No. 1,479,112, issued to W. Spenks on Jan. 1, 1924 and entitled "Light Absorber For Cameras" where the patentee shows a series of rearwardly projecting septums located behind the lens of a camera for preventing flare or fogging by intercepting peripheral light rays passing through the lens.
Another solution particularly suitable for non-folding type cameras is disclosed in copending U.S. application Ser. No. 620,924 filed on Oct. 9, 1975 in the name of Bruce K. Johnson and entitled "Anti-Flare Structure For Photographic System" now U.S. Pat. No. 4,057,815. In this disclosure the applicant shows a rigid opaque exposure chamber which employs specularly reflective interior wall surfaces and serrations to control stray radiation.
However, none of the foregoing solutions are suitable for use with folding type cameras which are collapsed into a compact size suitable for storage and transport.
There are a number of U.S. Patents which describe shutter housing structures having flare reducing means located behind a photographic objective lens. Among these are U.S. Pat. No. 2,877,699 issued to M. N. Fairbanks on Mar. 17, 1969 and entitled "Photographic Apparatus", U.S. Pat. No. 3,044,376 issued to K. Gebele on July 17, 1962 and entitled "Photographic Apparatus", and U.S. Pat. No. 3,709,129 issued to Karl-Heinz Lange on Jan. 9, 1973 and entitled "Camera With Retractable Objective", each of which disclose cameras provided with conically shaped projections coaxial with the lens and extending rearwardly toward the film, the projections having a stepped or rigid surface for reducing flare. A disclosure similar to the last three mentioned patents showing a conical projection extending rearwardly of a lens is shown in U.S. Pat. No. 3,479,945 issued to C. Koch on Nov. 25, 1969 and entitled "Photographic Focusing Camera". However, each of these shutter housing structures apparently have limited effectiveness as major flare reducing means but rather are intended for use in reducing local reflections on surfaces located immediately behind a lens and which generally would not extend into a camera's exposure chamber because they would interfere with folding the camera.
Solutions for reducing flare in folding type cameras have also been proposed in the patent literature. In U.S. Pat. No. 1,291,405 issued to L. X. Champeau on Jan. 14, 1919 and entitled "Camera", the patentee discloses a camera having an accordian type bellows for interconnecting a lens to a film plane in light-tight fashion. Extensions of the surfaces forming the accordian folds are provided to project toward the optical axis of the lens beyond the apical edges of the folds to serve as baffles to prevent flare light. While this solution is adequate for the type of bellows and camera structure disclosed, it would not be readily adaptable for use in a reflex folding camera of the type with which the present invention is concerned. More particularly, the present invention is concerned with the provision of a flare prevention means for use in a compact folding reflex camera of the type disclosed in U.S. Pat. No. 3,678,831 issued to James G. Baker on July 25, 1972 and entitled "Compact Folding Reflex Camera" and having an opaque elastic envelope which defines an exposure chamber such as that disclosed in U.S. Pat. No. 3,682,068 issued to Frank M. Stieger on Aug. 8, 1972 and entitled "Light Envelope". One of the sources of flare in cameras of the foregoing type is caused by reflections from interior surfaces of the elastic envelope which is stressed upon erection of the camera to form a plurality of generally planar surfaces interconnected to define its exposure chamber.
With elastic light-tight envelopes of the foregoing type, it is necessary to provide a flare prevention means which reduces stray reflections from their interior surfaces while still satisfying the requirement of compactness. In U.S. Pat. No. 3,727,529 issued to Charles DeJesus et. al. on Apr. 17, 1973 and entitled "Combination Flare Baffle and Light Seal for Reflex Camera", the patentees teach the use of a single movable baffle fabricated of a metal stamping to reduce stray light. This solution, while being consistent with compactness, reduces the effects of stray reflections for only certain local interior surfaces of the exposure chamber.
Likewise in the commercial version of Polaroid Corporation's "SX-70 Camera", there is provided a series of spaced apart baffles located on one surface of its elastic light-tight envelope and extending transverse to the optical axis of the camera's lens to reduce stray reflections from that particular surface. Therefore, a need exists for a major flare prevention means for reducing substantially all internal stray reflections which may contribute to flare effects in a compact folding reflex camera having an elastic light-tight envelope of the type referenced. Consequently, it is a primary object of the present invention to satisfy this need.
Another object of the present invention is to provide a collapsible flare baffle insert for a compact collapsible camera.
Other objects of the invention will in part be obvious and will in part appear hereinafter. The invention accordingly comprises the apparatus possessing the construction, combination of elements, and arrangement of parts which are exemplified in the following detailed disclosure.